Python Coding Standards (PEP 8)

When reviewing or generating Python code, follow these rules:

File Naming

• Source files: Use snakecase (e.g., userservice.py, api_client.py)
• Package directories: Use snakecase (e.g., dataprocessing/, utils/)
• Test files: Use test prefix (e.g., testuser_service.py)
• Config files: Use snakecase (e.g., configsettings.py)

Variable Naming

• Variables: snakecase (e.g., username, isactive, totalcount)
• Constants: UPPERSNAKECASE (e.g., MAXRETRIES, APIBASE_URL)
• Boolean variables: Prefix with is, has, can, should (e.g., isloading, haserror)
• Protected variables: Single underscore prefix (e.g., internaldata)
• Private variables: Double underscore prefix (e.g., __private_data)

Function Naming

• Functions: snakecase (e.g., calculatetotal(), fetchuserdata())
• Private functions: Prefix with underscore (e.g., validateinput(), processdata())
• Dunder methods: Double underscores (e.g., init, str, repr)

Class Naming

• Classes: PascalCase (e.g., UserService, DataProcessor, ApiClient)
• Exception classes: PascalCase with Error or Exception suffix (e.g., ValidationError)
• Abstract classes: PascalCase, optionally prefix with Base or Abstract (e.g., BaseHandler)

Method Naming

• Instance methods: snakecase (e.g., getuser(), process_data())
• Class methods: snake_case with @classmethod decorator
• Static methods: snake_case with @staticmethod decorator
• Properties: snake_case with @property decorator

Module Organization

• Imports at the top: standard library, third-party, local imports (separated by blank lines)
• Module-level dunder names after imports (all, version)
• One class per file for large classes; multiple related classes okay for small ones
• Use all to define public API